The present invention relates to a propulsion unit for motor land vehicles, and particularly to a unit of the type comprising a turbine which drives electrical generators which feed electric drive motors. Propulsion units of this type are particularly suitable for installation on public transport vehicles, such as urban and suburban buses, and for use in areas of high traffic density because the turbines, since they only have to drive electrical generators, can be controlled accurately to run in such a way that the pollutant content of the exhaust gases is minimised.
Such a prior propulsion unit comprised an internal combustion engine, in the case in point, a turbine, an alternator driven by the turbine, a battery charged by the alternator, and an electric motor which drives the wheels of the vehicle and which is itself driven by either the battery or the alternator, according to the operating conditions, under the control of an electronic control circuit incorporating sensors provided inter alia for the purpose of detecting the state of charge of the battery.
The presence of a battery, however, although necessary for meeting the requirements of low pollution when travelling in regions of high traffic density, considerably increases the overall weight of the vehicle.